Enclosed cutout having a fused load break device



May 27, 1958 R. NAKATA ENCLOSED CUTOUT HAVING A FUSED LOAD BREAK DEVICE Filed June 28. 1954 a a m 2 Z UNI FHWMWN IH W m g w w mm r 2 a F. m Vain .1 m a n m w m N q a ,3. w

l'lkhl l ll 4 \FIKIIIIII IIIIIIHIIIIHHHHHHNIHWH .514 H r vv lllll.llllllllllllflllll 1 United States Patent ENCLOSED CUTOUT HAVING A FUSED LOAD BREAK DEVICE Roy Nakata, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application June 28, 1954, Serial No. 439,621

4 Claims. (Cl. 200-114) This invention relates to a cutout having a load break device, and more particularly, to an enclosed cutout having a fused load break device.

It is an object of this invention toprovide an enclosed cutout with a reliable, low-cost, uncomplicated, and safe load break device.

My invention comprises an enclosed cutout having a fused load break device, said cutout comprising a pair of spaced terminal contacts positioned in a housing, said housing closed by a door, a current interrupting means mounted on an interior portion of said door adapted to span said pair of spaced terminal contacts when said door is closed to complete an electrical circuit therebetween, said current interrupting means having two spaced contacts adapted for engagement with said two spaced terminal contacts when said door is closed, said load break device comprising a.fused link positioned on said door, said fuse link having a lower current interrupting rating than said current interrupting means, one end of said fuse link electrically connected to one of said current interrupting means contacts, a movable bridging contact positioned on said doormovable from a position whereby said movable bridging contact electrically isolates another end of said fuse link from the other of said current interrupting means contacts to another position wherein said another end is in electrical contact with said other contact whereby said fuse link displaces said current interrupting means in said electrical circuit.

My invention further comprises an enclosed fused cutout having a fused load break device comprising two spaced terminal contacts positioned in a housing, a door for said housing, a main fuseholder positioned on an interior portion of said door, said main fuseholder having an upper and lower contact adjacent opposite ends thereof electrically connected by a main fuse link disposed within said main tfuseholder, another contact on said main fuseholder between said upper and'lower main fuseholder contacts, said upper and another main fuseholder contacts adapted to electrically engage said spaced terminal contacts when said door is closed, a cylindrical bore in said door extending generally parallel to said main fuseholder, a load break fuseholder positioned within said cylindrical bore having a load breakfuse link therein, said load break fuse link having a lower current interrupting rating than said main fuse link, an upper end of said load break -fuse link electrically connected to said upper contact, a contact adjacent a lower end of said load break fuseholder with the lower end of said load break fuse link electrically connected thereto, a movable bridging contact member movable along a line generally parallel to said fuseholders between said lower and another main fuseholder contacts and said load break fuseholder contact, said movable bridging contact member comprising an insulating material member having two electrically connected spaced contacts thereon, one of said contacts of said movable bridging Contact member engageable with said main fuseholder lower end and another contacts, the other of said contacts of said movable bridging contact member engageable with said load break fuseholder contact.

The features of my invention which I believe to be novel are set forth with particularity in the appended claims. organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing.

In the drawing, Fig. 1 is a side elevation view, partly in section, of a preferred form of my invention. Fig. 2 is a view of my invention identical to that of Fig. 1, partly broken away, after operation of the load break device thereof. Fig. 3 is a sectional view of my invention taken along the line 33 of Fig. 1. Like reference numerals will be used throughout the various figures to' indicate identical parts.

Referring now to the drawing, and more particularly to Fig. 1, shown therein is an enclosed fused cutout comprising an electrical insulating material or porcelain housing 1 having two spaced terminal contacts 2 and 3 therein. Housing 1 is closed by an electrical insulating material door 4 pivoted adjacent the lower end of housin 1 by a U-shaped hinge member 5 hooked on to a pair of spaced bearing members 6. See also Fig. 3.

Mounted on the inside of door 4 in spaced relation- I ship with respect to the interior surface of door 4 is a main fuseholder 7. Fuseholder 7 has contacts 8 and 9 positioned thereon adjacent opposite ends thereof. Lowerfuseholder contact 9 is a U-shaped member connected to the U-shaped hinge member 5 by a pin 10 or the like passing through the legs thereof, whereby. the lower end of the fuseholder 7 is held in spaced relationship with respect to the interior surface of the door 4..

Pin 10 passes through a tangentially disposed groove formed in a lower external surface portion of the fuse holder 7 whereby fuseholder 7 is axially immovable.

The upper end of fuseholder 7 is disposed between a pair of spaced electrical insulating material latching arms 11 integral with the door 4 defining a not shown circularlike opening therebetween whereby the upper end of the fuseholder 7 is held in spaced relationship with respect to the interior surface of the door 4. A pair of latching fingers 12 are adapted to engage the latching arms 11 to hold the door 4 closed. A main fuse link 13 is disposed within the fuseholder 7. Main fuse link 13 is electrically connected at its upper end to the contact 8, and at its lower end to the contact 9, as by mechanical attachment to the U-shaped hinge member 5 adjacent the base portion thereof.

Fuseholder 7 has another contact 14 thereon disposed between the contacts 8 and 9. When the door 4 is closed contact 8 will engage terminal contact 2, and contact 14 will engage terminal contact 3.

Formed within the door 4 is a cylindrical bore 15 extending generally parallel to the main fuseholder 7. Disposed within bore 15'is a load breakfuseholder 16 having a load break fuse link 17 disposed therein. Load break fuseholder 16 and load break fuse link 17 have a lower current interrupting rating than the main fuseholder 7 and main fuse link 13 whereby when the load break fuse link 17 is carrying the full load of the enclosed fused cutout load break fuse link 17 will be ruptured tointerrupt the load. 1 i

The upper end of load break fuse link 17 is electrically connected to the main fuseholder contact 8 by virtue of a spring contact finger 18 disposed on the interior surface of door 4 and continuously biased for engagement with contact 8. Finger 18 is connected by a pin or the like to a contact collar or the like disposed about the upper I My invention itself, however, both as to its 3 end of. fuseholder 16. The button head or the like of fuse link 17 is pressed into engagement with said collar by a spring or the like disposed between said button head anda closure cap 19 for the upper end'of bore 15.

Another spring contact finger 20 is disposed adjacent to the lower end of fuseholder 16 on the interior surface of the door 4. The lower end of fuse link. 17 is rigidly fastened to the lower end of fuseholder 16 by a contact sleeve 21 or the like passed over the exterior end of fuseholder 16 and the lower end of fuse link 17. A thumb bar 22 rides in a channel-shaped groove 23 formed in an interior surface portion of the door 4. Slide bar 22 is disposed between the main fuseholder contacts 9 and 14 and the load break fuseholder contact 20 and, can be moved along a line disposed generally parallel to the fuseholders 7 and 16. Slide bar 22 has two spaced electrically interconnected contacts 24 and 25 disposed on opposite sides thereof. Contact 24 is substantially longer than contact 25 and is adapted to electrically engage the main fuseholder contacts 9 and 14. Contact25 is disposed onthe side of slide bar 22 positioned in the channel-shaped groove 23 and is adapted to electrically engage. the load break fuseholder contact 20. See also Fig. 2.

In the Fig. l position of the bridging contact member an electrical circuit is established between terminal contacts 2 and 3 by contact 8, fuse link 13, U-shaped hinge member 5, contact 9, contact 24, and contact 14. Said electrical circuit can be interrupted by hinging the door 4 open.

terminal contacts 2 and 3 and the main fuseholderv contacts 8 and 14. Said heavy electrical arcing causes damage to the cutout parts, endangers the safety of the operatoror lineman, and may result in a major short circuit.

In my invention the above mentioned disadvantages of manually breaking the load by hinging the door 4 open are substantially avoided in a reliable, low-cost, uncomplicated, and safe manner. To break the load the slide bar 22 is moved from the Fig. 1 position to the Fig. 2 position. In the Fig. 1 position of the slide bar 22 the bridging contact member electrically bridges the main fuseholder contacts 9 and 14 while each of the main fuseholder contacts 9and 14 is electrically isolated from the load break fuseholder contact 20. Accordingly, in the t Fig. 1 position of the slide bar 22 full load is being carried by the cutout fuse link 13. As the slide bar 22 is moved upwardly to the Fig. 2 position, the bridging contact member will pass through an intermediate position whereby. the contact 24 will still be in electrical engage ment with the main fuseholder contacts 9 and 14 while the contact 25 is in electrical engagement with the load break fuseholder contact 20. In said intermediate position'of the slide bar 22, the fuse links 13 and 17 will be connected electrically in parallel. The rating of the load break fuse link 17. has a predetermined rating whereby said load break fuse link. 17 will .not be ruptured when connected electrically in parallel with fuse link 13. At the upper limit. of. movement of the slide bar 22, the contact 24 will no longer bridge the main fuseholder contacts 9 and 14.. Contact 25 will be in engagement with the spring contact finger 20 and the contact 24 will be'inengagement solely'with'the main fuseholder contact 14; Accordingly, in; theFig. 2 position of the bridging contact member-"full load will be carried'by'the load However, such. a procedure for breaking the load may result in heavy electrical arcing between the break fuse. link 17. Inasmuch as the load break fuse link 17 has a current interrupting rating less than the main fuse link 13, it will be ruptured when carrying full load. When the fusible portion of fuse link 17 is ruptured electrical arc extinguishing gases will be generated by the fuseholder 16, as will be obvious to those skilled in the art, whereby the lower broken end of fuse link 17 will be expelled out of the lower open end of the fuseholder 16. The door 4 can now be opened free of any exposed electrical arcing.

Prior to making the load, the load break device of my enclosed cutout can be refused by removing the closure cap 19 and loosening the thumb screw adjacent to the contact sleeve 21 of the load break fuseholder 16. Prior to closing of the door 4 to make the load, the slide bar 22 is withdrawn from the cutout housing 1 from the Fig.

7 2 position to the Fig. 1 position, whereby the upper hooked end of the contact 24. engages the main fuseholder contact 14.

While there has been shown and described a particular embodiment of the invention, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention, and that it is intended by the appended claims to cover, all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An enclosed cutout'having a fused load break device, said cutout comprising, a pair of spaced terminal contacts positioned in a housing, said'housing closed by a door, a current interrupting means mounted on an interior of said door adapted to span said pair of spaced terminal contacts when said door is closed to complete an electrical circuit there'oetween, said current interrupting means having two spaced contacts adapted for engagement with said two spaced terminal contacts when said door is closed, said load break device comprising a fuse linkpositioned on said door, said fuse link having alower current interruptingrating than said current interrupting means, one end of said fuse link electrically connected to-one of said current interrupting means contacts, a movable bridging contact positioned on said door movable from a position whereby said movable bridging contact electrically isolates another end of said fuse link from the other of said current interrupting means contacts to another position wherein said another end is in electrical contact with said other contact and said fuse link displaces said current interrupting means in-said electrical circuit.

2. An enclosed fused cutout having a fused load break device, said cutout comprising two spaced terminal contacts positioned in a housing, said housing closed by a door, said door having a fuscholder positioned on an interior portion thereof, said fuseholder having a contact at opposite ends thereof-electrically connectedby a main fuse link, another contact positioned on said fuseholder between said opposite end contacts, one of said opposite end contacts and said another contact adapted for electrical engagement with said two spaced terminal contacts when said door is closed, a load break fuse link positioned on said door, said load break fuse link having a lower current interrupting rating than said main fuse link, one end of said load break fuse link connected to tact are electrically connected while each is electrically isolated from said other opposite end contact.

3. An enclosed fused cutout having a fused load break device comprising two spaced terminal contacts positioned in a housing, a door for said housing, a main fuseholder positioned on an interior portion of said door, said main fuseholder having an upper and lower contact adjacent opposite ends thereof electrically connected by a main fuse link disposed within said main fuseholder, another contact on said main fuseholder between said upper and lower main fuseholder contacts, said upper and another main fuseholder contacts adapted to electrically engage said spaced terminal contacts when said door is closed, a cylindrical bore in said door extending generally parallel to said main fuseholder, a load break fuseholder positioned within said cylindrical bore having a load break fuse link therein, said load break fuse link having a lower current interrupting rating than said main fuse link, an upper end of said load break fuse link electrically connected to said upper contact, a contact adjacent a lower end of said load break fuseholder and a lower end of said load break fuse link electrically connected thereto, a movable bridging contact member movable along a line generally parallel to said fuseholders between said lower and another main fuseholder contacts and said load break fuseholder contact, said movable bridging contact member comprising an insulating material member having two electrically connected spaced contacts thereon, one of said contacts of said movable bridging contact member engageable with said main fuseholder lower and another contacts, the other of said contacts of said movable bridging contact member engageable with said load breakfuseholder contact.

4. A fused cutout having a fused load break device comprising a housing having a door, two spaced terminal contacts in said housing and a main fuseholder mounted on said door and spaced from the interior surface thereof, said main fuseholder having an upper and lower contact adjacent opposite ends thereof and a main fuse link within said main fuseholder connected at its opposite ends to said upper and lower contacts, said main fuseholder having another contact thereon between said upper and lower contacts, said upper and another contacts engageable with said two terminal contacts when said door is closed, a cylindrical bore in an outer portion of said door extending generally parallel to said main fuseholder, a load break fuseholder having a load break fuse link therein disposedin said cylindrical bore, an upper end of said load break fuse link electrically connected to said upper contact, a load break fuseholder contact disposed adjacent said interior surface substantially opposite said main fuseholder another contact, a lower end of said load break fuse link elec trically connected to said load break fuseholder contact and said main fuse link and fuseholder having a higher current interrupting rating than said load break fuse link and fuseholder, a movable bridging contact member disposed between said main fuseholder and interior surface and movable therebetwcen along a line generally parallel to said fuseholders, said bridging contact member in one position thereof electrically bridging said main fuseholder lower and another contacts while each is electrically isolated from said load break fuseholder contact, said bridging contact member in another position thereof electrically bridging said main fuseholder another and lower contacts and said load break fuseholder contact whereby said fuse links are connected electrically in parallel, said bridging contact member in still another position thereof electrically bridging said main fuseholder another contact and load break fuseholder contact while each is electrically isolated from said main fuseholder lower contact, said bridging contact member comprising an electrical insulatingmaterial rod having two spaced electrically interconnected elongated contacts thereon, one of said elongated contacts being substantially longer than the other, in said one position said one elongated contact engaged with said main fuseholder lower and another contacts and said other elongated contact out of engagement with said load break fuseholder contact, in said another position said one elongated contact engaged with said main fuseholder lower and another contacts and said other elongated contact engaged with said load break fuseholder contact, in said still another position said one elongated contact engaged with said main fuseholder another contact and out of engagement with said main fuseholder lower contact and said other elongated contact engaged with said load break fuseholder contact.

References Cited in the file of this patent UNITED STATES PATENTS 2,255,300 Schultz Sept. 9, 1941 2,256,232 Bennett Sept. 16, 1941 2,269,130 Schultz Jan. 6, 1942 2,287,499 Smith June 23, 1942 2,519,289 Roman et al. Aug. 15, 1950 2,548,129 Steinmayer Apr. 10, 1951 

